A catalytic converter is a member that is installed on the exhaust line of the motor vehicle, upstream of a silencer. It is a filter designed to reduce the emissions of pollutant gases (HC, CO, NOx etc.). More particularly, it involves a ceramic block comprising channels that are coated internally with a catalyst and that the exhaust gases pass through.
For some time now, governments, notably those of the European Union, have enacted standards that have forced manufacturers to install catalytic converters of increasing efficiency and to offer an onboard diagnostic service for diagnosing the performance of the converters as they age.